When "Hail to the Chief" stops playing, most former leaders of the free world learn to sing a new tune

Former President George W. Bush, left, and his wife Laura Bush wave as they depart Andrews Air Force Base, Maryland, Tuesday, Jan. 20, 2009.

"Never did a prisoner, released from his chains, feel such relief as I shall on shaking off the shackles of power," declared Thomas Jefferson upon departing the presidency. At that point he could retreat to Monticello, read Plato in Greek, plan and plant his University of Virginia. "I have given up newspapers in exchange for Tacitus and Thucydides," he wrote to John Adams, "and I find myself much the happier."

But it is the rare modern President who retires to his farm and his library, unless by library we mean a multimillion-dollar monument to his vital...